Redermination of 9,9′-bianthracene-10,10′(9H,9′H)-dione

The crystal structure of the title compound, C(28)H(18)O(2), was originally determined by Ehrenberg [(1967 ▶). Acta Cryst. 22, 482–487] using intensity data obtained from Weissenberg photographs. The current determination provides a crystal and mol­ecular structure with a significantly higher precision and presents standard uncertainties on geometric parameters which are not available from the original work. The mol­ecule lies on a crystallographic twofold rotation axis which bis­ects the C—C bond [1.603 (3) Å] which joins the two anthracen-9(10H)-one units.